As a conventional LED light source device, there has been known one described in, for example, the following patent document 1. In such an LED light source device, a translucent member made of acrylic is disposed on a front side of an LED array for which LEDs that emit visible light forward are juxtaposed, and a space between the LED array and translucent member is sealed by a transparent resin made of silicone. Then, visible light from the LEDs is emitted via the transparent resin and translucent member.